Oscillating generator particularly designed for polyphonic musical instruments



Jan. 21, 1969 R. BIE-Rl. ET AL y 3,423,514

OSCILLATING GENERATOR PARTICULARLY DESIGNED FOR POLYPHONIC MUSICAL INSTRUMENTS Filed NOV. 27, 1962 Sheet `Of` 2 ULARLY DESIGNED FOR POLYPHONIC MUSICAL INSTRUMENTS Sheet Filed Nov. 27, 1962 W R E MN @WJ mi /M M t u w m03 4 Z iw f J fm lvl 1lwww! iw! ull {N} 1-] .MHA m E., www. l .maf i, Er Nm@ uw @NNW MAQ, m B x Nu di wv NK QW 1j N d uw T::I:CCIT Z \N MNM NN WN NN QN N United States Patent O GSCILLATING GENERATOR PARTICULARLY DESIGNED FOR PGLYPHUNIC MUSICAL INSTRUMENTS Richard Bierl and Ernst Zacharias, Trossingen, Wurttemberg, Germany, assignors to Matth. Hohner AG., Trossingen, Wurttemberg, Germany, a corporation of Germany Filed Nov. 27, 1962, Ser. No. 241,107 Claims priority, application Italy, Dec. 1, 1961,

21,734/61, 686,462 U.S. Cl. 8f4-1.15 30 Claims Int. Cl. Glllh 3/00 deflects or deforms a resilient oscillatory member, such as a reed, so that, when the key is depressed to disengage the abutment or dome from the mechanical oscillator the latter vibrates freely.

A feature of the present invention is a novel design of the striking member as a key extension detachably carrying the elastic dome or abutment. In accordance with this aspect of the invention, the abutment or dome is designed as a multilayer element with each of the several layers having different properties. By the design of the abutment or dome in accordance with the invention, the abutment, when engaged with the oscillator, is compressed and exerts a damping effect, but the mechanical oscillator cannot indent the striking surface of the abutment to any appreciable extent. If such indentation were to happen, it would, in time, permit the oscillator to have a deflection out of correspondence with the admissible limits.

To this end, the elastic dome or abutment preferably comprises an inner or intermediate pad or cushion of very soft material, such as a foam rubber type of material, and a leathery or felt-like layer of material facing the oscillator, this latter layer of material being finer, harder, and more flexible than the intermediate layer of foam rubber consistency. The oscillator engaging layer can also be a very finely porous cellulose rubber, but preferably is a thin and relatively soft strip of leather which has its smooth side cemented to the considerably softer inner layer of foam rubber-like material and has its fibrous side facing the oscillator. These two layers can be effectively bonded by means of an adhesive which remains soft.

A particular advantage of the multilayer abutment of the invention resides in the fact that it limits penetration of the oscillator into the abutment, so that the changes in position of the oscillator remain so slight that they do not affect substantially the amplitudes of the decaying oscillations, and thus do not affect the transformation of the mechanical oscillations into electrical oscillations. As a consequence, the matching of the properties of various oscillating generators of a polyphonic instrument can be maintained readily.

The attainment of this prerequisite of a musical instrument is further enhanced by the invention abutment design, as the electro-mechanical transducing system has only a negligibly small transmission factor within the maximum deflection range of the oscillator.l Therefore,

the repose deformation or defiection of the oscillator, wherein there are slight and unavoidable changes of the oscillator repose position, has hardly any effect. The arrangement is further advantageous with respect to the limitation of clicking noises which are apt to be produced Wherever harder abutments are used, such as those formed completely of leather. Clicking noises are also avoided in the event that there should be a certain degree of hardening of the striking surface of the dome.

The intermediate layer or cushion of the abutment or dome is cemented to an inner or abutment mounting layer of rubbery material, and this inner layer is formed with an opening whereby the abutment may be disengageably coupled to a key extension.

The low transmission factor is of advantage, for example, when used with a capacity type transducer. In such a case, a slight deflection of the oscillator in the neighborhood of its repose position will effect only slight changes in capacity value as compared with equally large deflections, for example in the range of the midposition of the oscillations or in the range of deflection on the side opposite the position of repose deflection. Thus, and as an important feature of the invention, there is obtained an initial reduction of interference pulses which might occur upon the reengagement of the oscillator by the abutment as the key returns to its rest position.

A further advantageous feature resides in the formation of the upper ends of the stationary electrodes, cooperating with the mechanical oscillator, in such a manner that they are symmetrical with respect to the oscillator deflection so that the curves of the electrical oscillations become asymmetrical, Thereby, even harmonies in the spectrum are relatively abundant, which contributes to clarity of tone and, in effect, to the producing of a sound which is similar to that produced by a piano.

As a feature of the invention, an increase in the amplitude of oscillation may be obtained by providing the striking surface of the abutment or dome with a dura-ble, pressure-sensitive adhesive so that, when the key is depressed and the key extension is moved in a direction to disengage the oscillator, the oscillator itself is moved to some extent in the same direction, until the restoringv force of the oscillator exceeds the strength of the adhesive, at which time the oscillator is released to vibrate freely.

The problem of providing a proper adhesive is manifold, as will be understood when it is considered that a very great number of proposals have been made for obtaining permanent adhesive bonds, commencing with the first rubber adhesives and continuing with the more modern organic or semiorganic adhesives. The wide range of art on the subject of adhesives is an indication that the mechanics of adhesion, aside from specialized examples, is very obscure and involved.

For example, a frequently used characteristic of adhesives is the `designation semiliquid or very soft consistency, but such a characteristic does not necessarily mean that any particular adhesive is applicable to a special set 0f circumstances. This is true, in particular, of silicone base adhesives. Considering only resins, rubbers, or pastes, in each instance there are so many types 0f silicones, as well as a large number of other semiliquid or very soft adhesive substances, that each group will contain some examples which will, over an extended period of time and under varying conditions, prove to be eminently suitable in the degree of efficiency. However, this is not always the case. Thus, one type of organo-poly-siloxanes is marketed both as a resinexpressly useful as an adhesive and also as a resin which is useful as a varnish and which necessarily dries in the air and therefore loses its adhesive properties after a lapse of time. In addition to some adhesives which have a definite adhesive strength, there are others which do not exhibit any adhesiveness with respect to certain types of materials, such as certain plastic composition materials. In the particular case of unvulcanized siliconerubber-coatings, there are many which are cold setting and thus have a changeable degree of adhesiveness, and there are others which do not harden and which retain their adhesive strength only under special conditions, it being necessary, for example, to avoid the inclusion of any impurities and to avoid the inclusion of any fibers brought into bonding relation with the adhesive.

For the purposes of the present invention, an adhesive their adhesive strength, only under special conditions, it istics, both with respect to the supporting medium and to the oscillator as well as with respect to its intrinsic nature. If it is further considered that all possible residue of the adhesive must be removed from the oscillator so that the latter may not be muted by accumulation of adhesion thereon, then resort must be had to the characteristic that the bonding force of the adhesive with respect to the intermediate elastic cushion must be greater than its cohesion, and the cohesion must be greater than the adhesion of the adhesive to the material from which the oscillator is made. Of these several characteristics, none `but the cohesion is a constant value of the material itself. In the case of adhesion, it is either the supporting material of the adhesive or the oscillator, and particularly the surface or chemical characteristics of the supporting material or the oscillator, which play a substantial role. The adhesive force is furthermore strongly influenced by the form of the supporting material, such as, for example, its porosity in .the case of a foam plastic. In the latter case, the adhesion is inuenced by the diameter of the capillaries and the difference between the surface tensions of the two materials with respect to the atmosphere.

Considering all these factors, an adhesive useful in the present invention is one which has a high viscosity value, of the order of from fifty thousand to one million centistokes (cst.). An example of a suitable adhesive of this type is a pressure sensitive silicone adhesive such as manufactured by Dow Corning Corporation of Midland, Mich., which is an adhesive which does not dry but always remains tacky.

In joining the several layers of the dome or abutment, and particularly 4where the striking surface consists of a thin and relatively soft leather strip having its smooth surface cemented to a considerably softer layer of a foam rubber-like material, only the leather layer will be saturated with the adhesive since the smooth side inhibits the permeation of the adhesive. In this case, it is advisable to use as an adhesive a nondrying resin or oil having a viscosity of from fifty thousand to one million cst., particularly of the organo-poly-siloxane group and possibly with a small admixture of phenyl.

A further feature of the invention resides in the construction of the mechanical-electrical transducer so as to take advantage of the novel characteristic of the striking abutment or dome. The part of the transducer cooperative with the mechanical oscillator for conversion of mechanical oscillations into electrical oscillations, and which may 'be termed an electrode or pole shoe, is adjustable for each mechanical oscillator. Thus, Where reeds are used as mechanical oscillators, a metal strip or a strip with a metal surface may be subdivided by means of transverse slots so that the sections thereby formed are positioned in a plane which is parallel to the oscillation-direction of the reeds or perpendicular to the general planes of the reeds, while being separated from the latter, or from their positions of maximum oscillating deection, by the least possible gap. Adjustment may be effected simply by bending the individual strips toward or away from the associated mechanical oscillator, although adjusting `screws can be used as the adjusting means. This same type of cooperating electrode structure may be used not only in capacity type transducers but also in inductive type transducers. By the use of this type cooperating electrode strip, there can be obtained, during manufacture, a uniform tonality as well as volume and timbre differences between the individual tones, since the tips of the individual reeds may be correspondingly adjusted in position relative to their c0- operating electrode or pole shoes.

With both a capacity transducer and an inductive transducer, the individual oscillator assemblies may be joined into groups so that the output of the individual groups may be amplified as desired and independent of other groups. In the case of a capacity type transducer, the ldifferent groups can be connected with different RC high pass filters, or the amplilication of the different groups can be varied by the utilization of different types of iixed capacity. The same principle holds true for inductive transducers, wherein the number of turns of a winding may -be varied.

As still a further feature of the invention, the mechanical oscillators are preferably produced from a stainless or non-oxidizing material, particularly a stainless steel. Aside from the usual corrosion inhibiting properties of this material, this material is particularly valuable for use with the mechanical oscillators since the adhesive need not be so highly neutral from the chemical standpoint.

For an understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings. In the drawings:

FIG. 1 is a part side elevational and part sectional view of a mechanical oscillator arrangement embodying the invention;

FIG. la is an enlarged part elevational and part sectional view of an abutment or dome embodying the invention;

FIG. 2 is a partial plan view of a polyphonic musical instrument incorporating the mechanical oscillator of the invention;

FIG. 3 is a vertical sectional view taken on the line 3-3 of FIG. l;

FIG. 4 is a partial elevational view of one form of electrode strip embodying the invention;

FIG. 5 is a view similar to FIG. 4 illustrating another embodiment of the electrode strip;

FIG. 6 is a side elevational view, partly in section, illustrating a further form of electrode strip;

FIG. 7 is a schematic wiring diagram illustrating the Igrouping of mechanical oscillators in accordance with the invention;

FIG. 8 is a part elevational View and part schematic wiring diagram of an inductive transducer used with the invention; and

FIG. 9 is a plan View corresponding to FIG. 8.

Referring to the drawings, a plurality of white keys 1 and black keys 2 are rockably mounted on a saddle 3 secured to a base plate 4. The keys 1 and 2 are Spring biased (not shown) in such a manner that the key wires 5 of the black or half-one keys 2 engage a soft contact surface 6 on a buffer strip 7, while the white or fullnote keys 1 are formed with lugs 8 engaging a soft contact surface 9 on a strip 10. The spring bias holds keys 2 against the surface 6 and keys 1 against surface 9 under pressure, so that the keys are positioned in uniform. relation while they are at rest. Each key Wire 5, with which the keys 1 are also provided, has a terminal or end section 11 which is circular in cross section. Each end section 11 carries a member 12 of rubber or rubber-like material which is apertured to receive the end section 11 of the key wire. The aforementioned multilayer cushion 13 is cemented to the member 12. The cushion 13 comprises an intermediate layer 14, of very soft or rubber foam-like material, and a thin superimposed layer 15, of leather or leather-like material.

In the rest position of each key, the associated cushion 13 carried by member 12 bears with sufficient force on a reed 16 so that the latter is flexed or deformed downwardly. The reeds 16 are mounted on a reed support 19 with the interposition of spacer ring 17, and are held in position by screws 18. Reed support 19 is mounted on a dielectric or insulating plate 20 which is positioned on and secured to the base plate 4. Plate 20 is provided with a slot 21 into which is inserted an electrode strip or strip electrode 22. As best seen in FIG. 2, the strip electrode 22 is subdivided by slots 22a in such a manner that each of the reeds 16, 23 24 and 25, each of which is tuned to a different pitch, has a separately adjustable section of the strip electrode 22 facing it.

The relatively thin oscillator contact surface is saturated with a high viscosity oil, of the type mentioned above, so that when a key is depressed to lift the striking member 12-15 mounted on the section 11 of key extension 5, the reed 16 is excited to oscillate not only as a result of the release of the pressure thereon but also yby virtue of the fact that the reed is moved in a direction away from the illustrated position by means of the adhesive effect thereon. The upper edges of the sections of electrode 22 are positioned in about the plane of the central position of the reed so that, in the case of upward deflections of the reed, the capacitance rbetween the electrode 22 and the reed 16 is at a minimum, while the capacitance is at a maximum in the proximity of the central position and, below this position, has a value differing to some extent from the maximum.

If a D.C. bias is applied, in a known manner, between the electrode strip 22 and the reeds, alternating voltages are derived between the electrode strip 22 and each of the reeds. These alternating voltages will have a symmetrical oscillation curve. Deflections in either direction fbeyond a given value thus effect changes in capacitance and also changes in the voltage. This is important in the present invention in that, when the key is in the rest position, slight movements of the key and thus slight movements of the reeds do not produce any voltage, so that restoration of the reed to its lbias position upon return of the key to its rest position will not generate any pulses. Such pulses would be lgenerated in the case where changes in deflection about the biased position of the reeds would also bring about changes of capacitance and voltage.

FIG. 4 is a partial elevational view of one form of electrode strip 22 insertable into the groove 21 of dielectric plate 20. As the electrode tips cannot be seen in this View, they have been indicated in broken lines which designate -both the ends of the reeds and the range of deection thereof.

As compared with the electrode strip design shown in FIG. 4, the design shown in FIG. 5 has the advantage that the range of practically linear capacitance change is magnified with deflection of the reed in accordance with various amplitudes of oscillation at different pitches. Thus, the pitch of the reed in the case of the electrode section indicated at 26 may be assumed to be lower than that in the case of the electrode section illustrated at 29'. In this form of electrode strip, as well as in the other forms, interference oscillations are suppressed in the range of the biased or stressed positions of the reeds to which they are deformed in the rest position ofthe associated keys. Consequently, the capacitance will not be changed to any extent even on deeper or greater depression of the reeds above a preselected value. On the other hand, the capacitance decreases in a linear manner in the opposite directions so that oscillations with low amplitude generate 10W voltages and those of high amplitude generate high voltages. As a result, there is attained the particular advantage that voltages of different magnitude may be generated dependent upon the intensity of the mechanical impulse imparted to the key, or where resort is had to utilization of the dynamics of key operation.

An effect similar to that obtained by the electrode strip arrangement shown in FIGS. 4 and 5 is also produced by the electrode arrangement shown in FIG. 6. In this case, the electrode strip 31 which is inserted into the slot of the insulating or dielectric plate 30 is subdivided into sections by means of slots so that each section is adjustable by bending, with respect to its distance from the oscillating end 32 of the associated reed 33. In contrast to the types of electrodes shown in FIGS. 4 and 5, the electrode shown in FIG. 6 extends upwardly beyond the highest possible deflection 34 of the reed 33, and the upper end of each section is bent inwardly substantially parallel to the associated electrode as shown at 35. Upon the occurrence of relatively high deflection, large capacitance changes occur between the electrode and the reed 33, and these may also occur as a consequence of the closer spacing of the reed 32 to the substantially perpendicular portion of the electrode 31. As a result, the voltage and the upper harmonic stability of the generator increase with the deflections of the reed in the same direction.

FIG. 7 schematically illustrates a grouped arrangement of the reeds or oscillators, with each group having different characteristics, in association with a capacity type transducer. The electrode strip 36, which is subdivided into the individual and mutually insulated segments, is again mounted in a dielectric plate 37 as previously described. The individual segments are combined electrically to form groups or banks, such as 38, 39, 40, 41 and 42 which may include fewer segments within the higher tonal range and a greater number of segments within the lower tonal range. These segments are connected to the transducer by means of the leads 43 through 47. One lead 49 of the D.C. potential source is connected to these leads through the high value resistances 48. The parallel condensers 50 are also connected between the other terminal of the D.C. source and the leads 43 through 47, and the load resistance 53 is connected to the leads through separating capacitances 51 and coupling resistances 52. The voltage impressed on load resistance 53 controls, through lead 54, the input of the following amplifier stages. Depending upon the values of the capacitors 50 and 51 and of the resistances 48 and 52, the relative contributions or outputs of the individual groups 38 through 42 can be adjusted both with respect to the potential value as well as with respect to the resultant tonal spectrum, thereby to provide whatever tonality is desired for the instrument.

FIGS. 8 and 9 schematically illustrate an inductive transducer arrangement. This inductive transducer arrangement includes a strip shaped electrode comprising the individual sections 55 through 62, which are pole shoes of ferromagnetic material. These pole shoes are inserted in a groove 63 of a metal base plate 64 of nonmagnetic material such as aluminium, the several sections 55 through 62 being separated by relatively small distances. The pole shoe segments carry a winding which is twisted from one section to the other so that those segments which face, for example, reeds 65 and 66 of relatively lower frequency carry fewer turns of the winding than those segments, such as the poles 61 and 62, which face the higher frequency reeds 67, 68. The bifilar arrangement of the -winding 61 is illustrated in FIG. 9, and the tips of the reeds, which are blocked by the pole pieces, are indicated in FIG. 8 by broken lines in their stressed positions. The ends of the bifilar pole shoe windings are connected through a matching transformer to a preamplifier 71 which is built into the housing of the musical instrument, and the output of the preamplifier is connected by means of a cable 72 with an amplifier 73 and a loudspeaker 74. It will be appreciated that the amplifier 73 and loudspeaker 74 can either be built into the housing of the musical instrument or separately housed, or the transformer 70 and preamplifier 71 could be either built into the musical instrument or into a separate housing.

The arrangement illustrated in FIGS. S and 9 provides a particularly good transformation of mechanical oscillations into electrical oscillations, and one wherein not only are interference pulses, caused by the deformation of the reeds into stressed positions, prevented, but also wherein there is produced a tone which is similar t that of a piano tone and wherein the dynamic differences of the mechanical reed oscillations are not reduced.

While specic embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention lmay be embodied otherwise without departing from such principles.

What is claimed is:

1. An oscillation generator comprising, in combination, a resilient mechanical oscillator element which, when excited, freely vibrates with a decaying oscillatory movement, said element having a rest position; means supporting said element for vibration; a movable control key operatively associated with said element; means biasing said key to a rest position; a finger-like support carried by said key; a damper pad on said support and, in the rest position of said key, engaging a freely vibratory portion of said element and deflecting the latter from its rest position whereby, upon actuation of said key, said damper pad will disengage said element for free oscillation of the latter; said damper pad comprising plural layers of material cemented in surface-to-surface engagement, and including an inner layer of material having a damping effect upon said element and an element-engaging layer of material resisting distortion by said element; and an electric pick-up in operative relation with said oscillator element, the transducer transmission factor of said pickup, in the range of rest position of said element, being relatively low.

2. An oscillating generator, as claimed in claim 1, including a layer of pressure-sensitive adhesive on the element engaging surface of said damper pad.

3. An oscillating generator, as claimed in claim 1, in which finger-like support is an extension of said key; said damper pad and said extension being cooperatively formed for disengageable attachment of said damper pad to said extension.

4. An oscillation generator, as claimed in claim 3, in which said inner layer is an intermediate layer which comprises very soft resilient material; and an inner mounting layer cemented to said intermediate layer and comprising resilient material; said mounting layer being apertured to disengageably receive said extension.

5. An oscillating generator, as claimed in claim 4, in which the cement securing said layers in surface-to-surface engagement is a cement which remains soft.

6. An oscillating generator, as claimed in claim 4, in which said element engaging layer is thinner, harder, and more flexible than said inner layer.

7. An oscillating generator, as claimed in claim 6, in which the material of said element engaging layer is selected from the group comprising felt-like or leather-like material.

8. An oscillating generator, as claimed in claim 7, wherein said element engaging layer is linely porous cellulose rubber.

9. An oscillating generator, as claimed in claim 7, wherein said element engaging layer is leather having its smoother face cemented to said inner layer.

10. An oscillating generator, as claimed in claim 1, in which said element engaging layer is saturated with an adhesive of the nondrying resin or oil type having a viscosity of titty thousand to one million cst.

11. An oscillating generator, as claimed in claim 4, in which the adhesive saturating said element engaging layer is an oil with a fibrous molecular structure.

12. An oscillating generator, as claimed in claim 11, in which said oil is a dimethyl-poly-siloxane oil.

13. An oscillation generator, as claimed in claim 1, in

which said mechanical oscillator element consists of nonoxidizing material.

14. An oscillation generator, as claimed in claim 13, in which the material of said mechanical oscillator element is stainless steel.

15. A polyphonic musical instrument comprising a plurality of oscillating generators, as dened in claim 1, and in which the musical range is subdivided into segments in which the damping properties of the damper pads differ from each other.

16. A polyphonic musical instrument comprising a plurality of oscillating generators, as defined in claim 1, in which said pick-up is a capacity type transducer; said element constituting one electrode of said transducer; said transducer including a second electrode operatively associated with said one electrode.

17. A polyphonic musical instrument, as claimed in clairn 16, in which each second transducer electrode associated with each respective mechanical oscillator element is individually adjustable relative to its associated respective oscillator element.

18. A polyphonic musical instrument, as claimed in claim 17, in which said second transducer electrodes comprise segments of a common second transducer electrode strip subdivided into segments each associated with one respective mechanical oscillator element.

19. A polyphonic musical instrument, as claimed in claim 18, in which each second transducer electrode segment is disposed adjacent the free end of its associated mechanical oscillator element and includes an extension extending inwardly over its associated mechanical oscillator element and positioned beyond the range of maximum vibration thereof.

20. A polyphonic musical instrument, as claimed in claim 19, in which each second transducer electrode segment is positioned in a plane extending substantially parallel to the line of oscillation of its associated mechanical oscillator element; each segment having an upper edge extending at an angle to such line to intersect the rest plane of its associated mechanical oscillator element.

21. A polyphonic musical instrument comprising a plurality of oscillating generators, as claimed in claim 1, in which said electric pick-up is an inductive type pick-up including said oscillator element as one electrode; the several pick-ups having second electrodes comprising pole shoes each adjacent the free end of a respective mechanical oscillator element; each pole shoe comprising a separate segment, and the segments being separated by slots and mounted on a common support, and a multiturn winding operatively associated with said pole shoe segments.

22. A polyphonic musical instrument, as claimed in claim 21, in which the number of turns of said winding on each segment increases in one direction along said common support.

23. A polyphonic musical instrument, as claimed in claim 16, in which said oscillation generators are arranged in groups, each group having an individual output circuit.

24. A polyphonic musical instrument, as claimed in claim 21, in which said oscillation generators are arranged in groups, each group having an individual output circuit.

25. In combination: a vibratile, musical reed element; an abutment member having a reed element engaging surface; said surface having a coating of adhesive substance; keying means having at least a iirst condition and a second condition for causing said abutment member to engage said reed element with said surface in said first condition so that said coating releasably secures said reed element to said abutment member and for causing said abutment member to disengage from said reed element in said second condition.

26. In a device for inciting dying-out vibrations in a vibrating body such as a reed or the like of a musical instrument having a movable key, a movable member for vibrating said body, means for coupling said movable member with said key and an abutment member carried by said movable member, an adhesive substance connecting said abutment member and said vibratory body for releasably securing together said abutment member and said vibratory body, said adhesive substance being effective to cause movement of said vibratory body by said movable member during only a portion of the movement of said movable member consequent upon depression of said key.

27. In a device according to claim 26, said abutment member being constituted of absorptive material, and said adhesive substance `being liquid and being absorbed by said absorptive material.

28. In a device according to claim 26, said `adhesive substance containing silicone oil of high molecular weight.

29. In a device according to claim 2S, said abutment member being constituted of absorptive material, and said adhesive substance being liquid and being absorbed by said absorptive material.

30. In a device according to claim 25, said adhesive substance containing silicone oil of high molecular Weight.

References Cited UNITED STATES PATENTS 6/1961 Jones 84-1.04

ARTHUR GAUSS, Primary Examiner.

S. D. MILLER, Assistant Examiner.

U.S. Cl. X.R. 

25. IN COMBINATION: A VIBRATILE, MUSICAL REED ELEMENT; AN ABUTMENT MEMBER HAVING A REED ELEMENT ENGAGING SURFACE; SAID SURFACE HAVING A COATING OF ADHESIVE SUBSTANCE; KEYING MEANS HAVING AT LEAST A FIRST CONDITION AND A SECOND CONDITION FOR CAUSING SAID ABUTMENT MEMBER TO ENGAGE SAID REED ELEMENT WITH SAID SURFACE IN SAID FIRST CONDITION SO THAT SAID COATING RELEASABLY SECURES SAID REED ELEMENT TO SAID ABUTMENT MEMBER AND FOR CAUSING SAID ABUTMENT MEMBER TO DISENGAGE FROM SAID REED ELEMENT IN SAID SECOND CONDITION. 